Интерактивная система просмотра системных руководств (man-ов)
glViewport (3)
>> glViewport (3) ( Разные man: Библиотечные вызовы )
NAME
glViewport
- set the viewport
C SPECIFICATION
void glViewport(
GLint x,
GLint y,
GLsizei width,
GLsizei height )
delim $$
PARAMETERS
x, y
Specify the lower left corner of the viewport rectangle,
in pixels. The initial value is (0,0).
width, height
Specify the width and height
of the viewport.
When a GL context is first attached to a window,
width and height are set to the dimensions of that window.
DESCRIPTION
glViewport specifies the affine transformation of $x$ and $y$ from
normalized device coordinates to window coordinates.
Let ($x sub nd$, $y sub nd$) be normalized device coordinates.
Then the window coordinates ($x sub w$, $y sub w$) are computed as follows:
x sub w ~=~ ( x sub nd ~+~ 1 ) left ( "width" over 2 right ) ~+~ "x"
y sub w ~=~ ( y sub nd ~+~ 1 ) left ( "height" over 2 right ) ~+~ "y"
Viewport width and height are silently clamped
to a range that depends on the implementation.
To query this range, call glGet with argument
GL_MAX_VIEWPORT_DIMS.
ERRORS
GL_INVALID_VALUE is generated if either width or height is negative.
GL_INVALID_OPERATION is generated if glViewport
is executed between the execution of glBegin
and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_VIEWPORT glGet with argument GL_MAX_VIEWPORT_DIMS
